according to several topics on the forum here (http://www.gravityhelp.com/forums/topic/setting-required-fields-in-advanced-fields and others) I don't think address line 2 is supposed to be required but as of 1.6.9 and 1.6.10 it appears to be required. I believe I was using 1.6.6 and everything was fun but now it is behaving oddly.